Abstract 4808
Background
NORE1A/RASSF5 is a tumor suppressor that is commonly inactivated in a variety of cancers. NORE1A is frequently down-regulated during tumor development and its inactivation often correlates with up-regulation of Ras activity. Although NORE1A was reported to be activated by NF-kB, its role in NF-kB signaling and the underlying mechanism have not been addressed. In this study, we explored the role for NORE1A in the regulation and function of the TNF-NF-kB pathway.
Methods
NORE1A effect on TNF regulation of inflammation, growth, and apoptosis was examined by flow cytometry, migration and invasion, and apoptosis assays. NORE1A regulation of TNF-NF-kB signaling was analyzed by quantitative RT-PCR, immunoblot, immunoprecipitation, and promoter luciferase assay.
Results
Upon exposure to TNF-a, NORE1A is induced by NF-kB signaling at the level of transcription while its activation suppresses TNF activation of NF-kB, indicating that NORE1A functions as a feedback terminator of TNF-NF-kB signaling. As predicted, NORE1A blocks TNF activation of pro-inflammatory gene transcription, epithelial-to-mesenchymal transition (EMT), invasion and migration. Mechanistically, NORE1A binds directly to TNF receptor I (TNFR1) and ubiquitin E3 ligase ITCH to promote ITCH-mediated K48-linked ubiquitination of TNFR1 and subsequent lysosomal degradation. Additionally, we identified that the PPXY motif of NORE1A interacts directly with ITCH using a series of deletion mutants. This interaction protects BAX from ITCH-mediated ubiquitination and thus activates its apoptotic function. NORE1A interaction with ITCH plays a crucial role for both TNFR1 degradation and BAX stabilization and activation.
Conclusions
In this study, we demonstrate first that NORE1A is a feedback terminator of TNF-NF-kB signaling, which directly antagonizes TNFR1 by facilitating the ITCH-TNFR1 interaction. Our study also shows that NORE1A binding to ITCH releases ITCH from BAX and activates BAX-mediated apoptosis. These data illuminate the mechanistic consequence of NORE1A inactivation in tumorigenesis.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Sung-gil, Chi.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
592 - Effects of novel targeted anticancer drugs on cytotoxicity, apoptosis, angiogenesis, EMT, drug resistance and autophagic mechanism
Presenter: Seyma Aydinlik
Session: Poster Display session 1
Resources:
Abstract
3235 - Delineating the mechanisms of alpha 1-3 fucosyltransferase FUT11 in ovarian cancer
Presenter: Qi Chen
Session: Poster Display session 1
Resources:
Abstract
3577 - The tyrosine kinase inhibitor Dasatinib blocks tumor growth, invasion and recurrence potential by interrupting the communication between cancer cells and their surrounding microenvironment in triple negative breast cancer
Presenter: Miriam Nuncia-Cantarero
Session: Poster Display session 1
Resources:
Abstract
1294 - Hsp90 inhibitors enhance the antitumoral effect of osimertinib and overcome osimertinib resistance in non-small-cell cell lung cancer cell models
Presenter: Jordi Codony-Servat
Session: Poster Display session 1
Resources:
Abstract
1559 - Expression of IL-17RA promotes cancer stem-like properties of colorectal cancer cells by Stat3 activation
Presenter: Chih-Yung Yang
Session: Poster Display session 1
Resources:
Abstract
1615 - Adaption of Pancreatic Cancer Cells to AKT1 Inhibition Induces the Acquisition of Cancer Stem-Cell Like Phenotype Through Upregulation of Mitochondrial Functions
Presenter: Hugo Arasanz
Session: Poster Display session 1
Resources:
Abstract
4793 - Bub3 is phosphorylated by the Ataxia-Telangiectasia Mutated Kinase in mitosis and required for activation of the mitotic spindle checkpoint in Breast Cancer
Presenter: Mingming Xiao
Session: Poster Display session 1
Resources:
Abstract
1448 - The regulation of INK4 locus by long non-coding RNAs
Presenter: Yojiro Kotake
Session: Poster Display session 1
Resources:
Abstract
1858 - Vascular Endothelial Growth Factor in Colorectal Cancer Pathology, Survival and Treatment
Presenter: Liz Baker
Session: Poster Display session 1
Resources:
Abstract
5011 - LCSCAF1 maintains cancer stem-like traits by stabilizing c-Myc protein and promotes metastasis and recurrence in lung cancer
Presenter: Tao Guo
Session: Poster Display session 1
Resources:
Abstract